1. Field of the Invention
The invention relates to a hydraulic control operation amount generation apparatus for an automatic transmission and a control apparatus for an automatic transmission, the automatic transmission having a plurality of engagement devices that are controlled by adjusting a hydraulic pressure in a working oil chamber.
2. Description of Related Art
In a conventional automatic transmission of this type, a gear ratio is switched by switching the respective engagement devices between an engaged condition and a disengaged condition. A control apparatus for this type of automatic transmission performs packing control to set the engagement devices in a standby condition (a so-called packed condition) immediately before the engaged condition by adjusting the hydraulic pressure in the working oil chamber. Japanese Patent Application Publication No. 2012-102810 (JP 2012-102810 A) and Japanese Patent Application Publication No. 2001-165290 (JP 2001-165290 A) disclose this packing control. According to a technique described in JP 2001-165290 A, when the packing control is performed, a target time (a preparation completion time) and a pack pressure (a preparatory pressure) of the packing control are retrieved from a map on the basis of an input shaft rotation speed of an engagement device and a temperature of working oil (automatic transmission fluid (ATF)), the preparation completion time is corrected on the basis of a remaining amount of working oil in the engagement device, and the preparatory pressure is supplied over the corrected preparation completion time.